With Leinster set to tackle Ulster in just the fourth one-nation Heineken Cup finale on Saturday, this week's Scrum Sevens looks back at some epic duels that saw two sides from the same country vie for the Super Rugby, Celtic league or Heineken Cup crown.

Crusaders 20-13 Blues, Super 12 Final, Eden Park, May 30, 1998

It was a match very few people expected the Crusaders to win with their hooker Mark Hammett even admitting that prior to the final his team-mates knew they were up against it. "If we'd been polled in that week, and had to give an honest answer, most of the boys, deep down, would probably have thought that the Blues would beat us," he recalled. And he had reason for his pessimism. The Blues had won the two previous Super Rugby titles and in their regular season meeting at Eden Park, the Auckland-based franchise had dispatched their arch rivals 31-24.

But the Crusaders upset the odds with Andrew Mehrtens slotting ten points and lock Norm Maxwell before the decisive score with just one minute of the 80 remaining. Mehrtens chipped the ball forward and winger James Kerr ran on to it to secure a 20-13 win for the Crusaders in the most dramatic fashion.

The inaugural Celtic League finale set the benchmark for all that followed. Both Irish sides finished top of their respective pools before battling through the knock-out stages where Leinster beat Newport and Glasgow and Munster accounted for Llanelli and Ulster. The final showdown was fairly close in the opening exchanges but a try from Michael Foley and a red card for Leinster's Eric Miller's put Munster firmly in the driving seat.

But Leinster rallied. Scores from the fresh-faced Gordon D'Arcy and Shane Horgan, coupled with Nathan Spooner's boot and the odd moment of genius from Lions star Brian O'Driscoll saw the 'hosts' power into a shock 24-15 lead. Anthony Horgan scored a late try for Munster, but it was Leinster's day as their 14-men shocked their great rivals much to the delight of coach Matt Williams.

"Everything was against us - a great side, a point against us, a man down and everyone saying we would crash," Williams said. "They didn't crash, they stood and went for it and won a very famous victory."

Toulouse became the second side in Heineken Cup history - alongside Leicester - to claim Europe's top prize twice after they overcame their French rivals in Dublin. At half-time it looked to be plain sailing for Toulouse. Four penalties from Yann Delaigue and Vincent's Clerc converted try gave Toulouse a healthy 19-0 lead. But with the benefit of a significant wind at their backs for the second half, Perpignan chipped away at Toulouse's advantage thanks to four penalties from Manny Edmonds, and came within a converted try at one point.

But it proved to be in vain as Delaigue nailed another penalty in the 80th minute extending the lead to 10 points. The Catalans scored late on with Pascal Bomati going over, but it proved to be too little too late leaving 'Le Rouge et Noir' to celebrate another European title.

It was a hard fought match in Edinburgh between the two French giants with Frederic Michalak's late penalty in front of the posts levelling the scores at 12-12 and taking the game into extra time. The mercurial Michalak then added another penalty at the start of added time to put Toulouse ahead only for Stade fly-half David Skrela to be given a chance to equalise moments later. He had already kicked impeccably during the first 80 minutes of the match as he nailed all of his side's points, but on this occasion the pressure got to him, and he missed. Michalak went on to slot a further drop-goal and Toulouse prevailed 18-12.

The game is also remembered for the notable absence of Toulouse boss Guy Noves during the trophy presentation. He was led away by police after he attempted to enter the crowd to celebrate the win with his family and a disgruntled Noves said of the matter: "This experience has spoiled what should have been one of the greatest days of my life. All I was trying to do was reach my son at the front of the audience to take him on to the pitch with me to see my players being presented with the cup.

"The security people and the police did not understand and they were quite rough with me. They took me to a small room and kept me there for more than 15 minutes. I calmed down and kept trying to tell them that I was the Toulouse coach and what I had been trying to do. Eventually, they understood. I am upset, my family is upset and the Toulouse supporters are upset."

The Crusaders were playing in their fifth-successive Super Rugby final and had won the title the previous year against the Brumbies. Boasting the likes of Dan Carter, Richie McCaw, Aaron Mauger and Chris Jack in their line up, the Crusaders were clear favourites. But in their way was a side featuring many familiar faces for the All Blacks with Piri Weepu spearheading the Hurricanes' charge to the showpiece event.

However, when kick-off came around, all previous match plans went out of the window with low-lying sea fog preventing the television cameras, the supporters and some of the players from seeing any of the action. The Crusaders ended up taking the match 20-13, thanks to Casey Laulala's try, but the match will be remembered for the ridiculous conditions it was played in and has since been nicknamed "Gorillas in the Mist" after the 1988 film.

The odds were heavily weighted in the Tigers' favour going into the match as eight days previous to this game, they had tied up the Premiership title in convincing fashion by sweeping Gloucester aside at Twickenham. Wasps had failed to qualify for the Premiership play-offs but still possessed that strutting peacock Lawrence Dallaglio in their ranks. And Wasps blew away their Premiership rivals in the first-half of the final with two well-worked set pieces.

From two separate lineouts, Eoin Reddan darted down the touchline and their move was then almost mirrored for Rafael Ibanez's score 21 minutes later. The Tigers had no answer to Wasps' ingenuity and although Andy Goode kicked three penalties, his Wasps counterpart Andy King possessed enough nous to keep the scoreboard ticking over as Wasps ran out 25-9 victors. It's perhaps only fair that the last word on the final went to Mr. Wasps himself - Dallagio: "Of all the finals that was number one without a doubt. Everyone was telling us that was the best Leicester team ever, so we must be the best Wasps team ever." Praise indeed.

Sharks 19-20 Bulls, Super 14 Final, Kings Park, May 19, 2007

The Sharks had topped the regular season table and a 17-3 victory over their South African rivals earlier in the campaign saw them enter the clash as favourites to claim the southern hemisphere's biggest domestic prize. A record crowd at the Sharks' Kings Park stadium were treated to a thrilling clash and arguably the most dramatic finish ever seen in Super Rugby.

With the clock ticking into added time at the end of the match, the Sharks looked to have the match sewn up as they led 19-13. JP Pietersen and Albert van den Berg had crossed for the Sharks with Percy Montgomery keeping the Bulls at bay with his boot. The Sharks' party was just warming up with the atmosphere reaching fever pitch.

Step forward Bryan Habana. The soon-to-be IRB Player of the Year jinked through the Sharks' defence and dotted the ball over the line much to Pretoria's joy and Durban's desolation. Derick Hougaard converted the score, putting them 20-19 ahead, and the Bulls had stolen victory from the jaws of defeat in the most sensational manner.